A pilot scale koji maker with a rotary perforated bed of 5 m diameter was employed for red-molded grains production. Monascus purpureus BCRC 31499 was the select strain for its higher production capacities of monacolin K and red pigment. The strain was first cultivated in a 120-l submerged type fermentor at 34oC and 2 vvm aeration rate with 60 rpm agitation for 5 days using 20% liquefied rice porridge as carbon source. The liquid red mold rice broth (>3.5 g/mL) was harvested for inocula and well mixed with cooked rice to an initial concentration of 2% v/w. The inoculated cooked rice then was directed into the koji maker, in which temperature and humidity profiles were kept at varied levels at different stages, respectively. Air was fed to remove fermentation heat while the perforated bed rotated slowly for providing mild agitation. Lag phase of the Monascus sp. in the koji maker was determined as 16 hrs by the time as koji temperature raised rapidly. Water was added into koji bed by a water curtain at 36th hour for keeping moisture content of the rice koji at 50% or above. At the final stage, temperature was adjusted to 34oC for directing red pigment production. After 7 days, 1200 kg high quality red mold rice was harvested each batch. In addition to rice, corn grains and defatted soybean flakes were also tested to produce red-molded grains following the same procedure for making red mold rice. Labor costs, space, and fermentation time were reduced tremendously in the red-molded grains compared with those made by traditional methods.